


The Short-Lived Second Youth of Lt. Col. John Sheppard

by unbirthdaydance



Category: Stargate Atlantis
Genre: De-aged John Sheppard, M/M
Language: English
Status: Completed
Published: 2012-06-15
Updated: 2012-06-15
Packaged: 2017-11-07 20:04:58
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,148
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/434857
Author URL: https://archiveofourown.org/users/unbirthdaydance/pseuds/unbirthdaydance
Summary: <blockquote class="userstuff">
              <p>Sheppard de-ages into a sixteen-year-old. Rodney McKay is Not Amused.</p>
            </blockquote>





	The Short-Lived Second Youth of Lt. Col. John Sheppard

**Author's Note:**

> A short twelve pages of de-aging silliness.

Rodney stared at the twelve-year-old. The twelve-year-old stared back at Rodney.

"I knew we never should have come to this planet," he groaned.

"Who are you?" asked the twelve-year-old.

~~~

Rodney made it back to Teyla and Ronon with the kid trailing behind him. Ronon, predictably, almost shot the kid before Teyla stopped him.

"This is Sheppard," Rodney told them.

"What the hell?" said Ronon.

"No, seriously," said the twelve-year-old. "What the hell are you?"

Rodney gave him a faintly scandalized look. "Watch your mouth! You're only twelve!"

"I think he looks more fifteen," Teyla interrupted calmly, scrutinizing the kid.

"I'm sixteen," said the kid, annoyed. "How do you know who I am?"

Teyla, Rodney and Ronon stared at each other for a long moment, then Teyla said: "I believe we should take him back to Atlantis."

~~~

When they got back to Atlantis, the only reason anyone believed that the kid was Sheppard was because he said he was, and because Rodney had been an eyewitness to his shrinking. It really wasn't all that difficult to understand why everyone had such a hard time with that idea. The kid really didn't look like Sheppard at all. He was short, for one thing, shorter than Rodney, tan, and skinny. True, he had a certain wiry musculature, but still, he was _skinny_. His hair was messy and fell down to his shoulders. His face was a lot more angular and a lot more sunburned than Rodney was used to as well, and he had freckles scattered across his nose and cheeks. He had an innocent, wide-eyed look that did not look like Sheppard at all.

And yet, he apparently was.

A wide array of medical tests by Beckett had soon confirmed that Sheppard really was Sheppard, and was in fine health for a skinny sixteen-year-old, and quite a lot of conversation had confirmed that he didn't remember anything beyond June fourth of his sixteenth year. Since his clothes were now too large, Beckett had procured from somewhere a pair of faded jeans, a t-shirt, sweater, socks and military-issue boots. The boots looked a bit out of place, and the sweater was still a tad too big, and an awful shade of green, but Sheppard didn't seem to mind.

He was taking this a lot better than Rodney would have at sixteen. Especially when by 'this', one meant actually being over two decades older and the military commander of a scientific outpost in another galaxy fighting a war with evil green space vampires with dreadlocks.

"So, I'm really cool, right?" he asked Rodney once all the interrogation was over and they'd headed down to the mess.

"Um," Rodney said, a bit incoherently. "Right."

"Sweet," said Sheppard-the-miniature, and seduced the current server into giving him triple helpings of pudding by way of his adorably innocent, sunburnt, freckled smile.

And Rodney McKay had so totally not just thought that Sheppard was innocently adorable.

Over a (late, after-mission) lunch, Sheppard persuaded them to tell him many stories of how he had defeated aliens and been basically awesome. Rodney listened to this glumly, because the Sheppard-of-legend sounded much more awesome than the real Sheppard had actually been.

"So," kid!Sheppard said brightly after he had eaten massive amounts of late lunch. "Someone want to show me around?"

~~~

Everybody liked de-aged!Sheppard.

This should not have been as depressing as it actually was, since basically everybody had liked adult!Sheppard as well. It just aggravated Rodney, because if people liked miniature!Sheppard so much, they might not mind if he never turned back. Rodney had soon found he preferred Sheppard's adult version, even though he liked Sheppard's kid version too, in spite of how annoying he was.

"I want him to turn back," Ronon told Rodney, when he'd complained about this for the fiftieth (or fifteen hundredth) time. "This kid can't kill things as efficiently. But he's still a good kid."

~~~

"Go away," Rodney told Sheppard-the-unfortunately-young.

"Why? I thought we were friends," replied said youngling, and did not go away.

"I," Rodney announced loftily. "Am friends with your older version. You, not so much."

Sheppard shifted slightly so that he was peering over Rodney's shoulder, at the tablet he was currently scribbling on. "I'm still the same person."

"No, you're not," Rodney told him. "You are an irritating, skinny teenager. My Sheppard is an intelligent, efficient adult."

"I wasn't an irritating adult?" asked the kid. "Damn, I've failed in my life goal."

That sounded so much like something the real Sheppard would have said, that Rodney swiveled his head around to stare at the kid, who shrugged and grinned at him.

"I've always been pretty sarcastic," he explained, blushing. "I didn't think I'd stop being that way."

Rodney tried to remember the last time he'd seen Sheppard blush, which was never, and said: "Yeah, well, you still are. But you were _mature_."

"Ah, well," sighed the kid, and leaned his chin on Rodney's shoulder. "I guess you can't have everything in life."

Rodney ignored the shivery, distracting feeling of someone breathing near his ear. "What, you didn't want to be mature, either?"

"Nah," said Sheppard lightly. "I figured I'd always be immature. Drove my parents crazy. Maybe," he added thoughtfully. "That's because they know I'm smarter than they are."

Rodney blinked. That last statement had sounded a lot like his own universal complaint against the world at large. Adult!Sheppard really never talked about his youth (which Rodney had always assumed to have been misbegotten) or his intelligence (which Rodney had always assumed to be substantial, but not genius-level, despite Sheppard's claims of 'I could've been Mensa'). Now, however, he had an accurate source of information...

"So," said Rodney carefully, and shifted sideways and around so he was facing the kid. "You're smarter than your parents?"

Sheppard rolled his eyes. "Obviously. You didn't know that? I thought you said I was intelligent as an adult, too."

"Yeah," Rodney pointed out. "But I've never met your parents."

"No?" Sheppard looked briefly startled, then thoughtful. "No, I guess you wouldn't have. Yeah, I'm smarter than them. They hate me, too," he added with relish.

"Is that because you're an annoying brat, or because they are legitimately awful?" asked Rodney, half-sarcastically, half-curiously.

Sheppard's mouth curved into a smirk. "Both? I _work_ at being a brat," he added smugly. "I piss them off whenever I can. You should've _seen_ their faces when I told them I was dropping out of school."

Rodney gaped at him, astonished. "You dropped out of school?"

"No," said Sheppard, and rolled his eyes. "I just threatened that I would. They were so horrified by the thought of me riding a motorcycle around the country for a living that they agreed not to disown me if I didn't go to college where they wanted me to. Not that I really care about the disowning," he added. "Just that the money would be nice. And, okay, maybe I wanted them to pay my way through college, even if I have got enough scholarships to sort of make it through on my own. If I worked a lot. Maybe."

Rodney took all this in, and said: "Wait, so you already have college scholarships? I thought you were sixteen. You don't graduate for another-"

"I already graduated," Sheppard interrupted. "I'm going to MIT in the fall."

 _That_ surprised him. Rodney had always assumed Sheppard had gone to college at some state university somewhere, or maybe just joined the Air Force. He'd had no idea he'd gone to _MIT._ At age _sixteen_.

"Why do you look so surprised?" demanded Sheppard suddenly. "Did I end up never going there or something?"

"I, uh, no," Rodney managed. "I just...you never talked about where you went to college. Or when," he added, feeling betrayed.

"Huh," said Sheppard, and peered over at his tablet again, apparently done talking about himself. He pointed a finger at one of the squiggles on the page. "Your math is wrong."

"Oh, sure," Rodney said sarcastically, pleased to be on familiar, unsurprising ground again. "Like you would know anything about _extremely advanced mathematics_..."

"I think," said Sheppard smugly. "That even I can add two and two, Doctor McGenius."

Rodney swore viciously, and bent to correct the error.

~~~

Elizabeth refused to put Sheppard Junior on a gate team. Sheppard sulked, but said he pretty much understood Elizabeth's reasons why. Teyla was relieved not to have a kid in command of their team. Rodney was disappointed, because that meant their team was off active duty until they managed to re-age Sheppard.

Ronon was disappointed too, but made up for it by teaching Sheppard how to shoot a gun, and kill someone with his bare hands.

~~~

"So, do you know how to fix me yet?" Sheppard asked one day. He'd developed the same annoying habit of showing up in Rodney's lab at random times and irritating the hell out of him as his older self had.

"No," said Rodney shortly. "I have not. And believe me, kid, I'm trying."

"Don't call me 'kid'," Sheppard advised, leaning against the lab table. "It sounds weird, coming from you."

"Fine then," Rodney snapped, wishing the _kid_ would go away and stop bothering him. "What should I call you? Buster, ace, shrimp, squirt, bucko, junior-"

Sheppard smirked at him and said: "You forgot 'Johnnyboy'. You should call me that. It would be hilarious."

Rodney scowled at him. "It would be undignified."

"Being undignified is _fun_ , though!" Sheppard protested. He then proceeded to spring backwards and sprawl into a shockingly good handstand. Headstand. Something like that.

Rodney gaped at him, and said: "Don't break anything!", not sure if he meant the lab equipment or Sheppard's bones.

Sheppard just grinned at him, and spun around, still upside down, on his head. His too-large shirt fell down over his head, revealing a tan that went further than Rodney really needed to know. His ponytail flopped awkwardly about, strands of hair coming loose from it. After a moment, he fell over and lay sprawled on the ground, red-faced and still grinning up at Rodney.

"That was fun," he said, a bit breathlessly.

"You're an _idiot_ ," said Rodney feelingly. "You were insane in your youth and it carried over into your adulthood."

"Yeah, whatever," said Sheppard, and scrambled to his feet. "Are you gay?"

Rodney choked on his own spit, and gaped at Sheppard again. "What? Why on Earth are you asking me that?"

"I _wondered_ ," said Sheppard defensively. "Can't I wonder?"

"No," Rodney told him firmly. "I am not gay, okay?"

"Oh," Sheppard mused thoughtfully. A wicked glint entered his eyes. "Then why were you staring at Sergeant Stackhouse's ass?"

Rodney choked on his own spit. Again. "I was _not_."

"Were too."

"Was not."

"Were too."

"Was not."

"Were _too_. It's a pity he didn't stare back- you've got a nice ass. Man, I'd pay money to see you two getting it on," he added reflectively, eyes going slightly distant.

Rodney very determinedly did not choke on his own spit yet again, and said: "You've got a filthy, horrible mind for a child, you know that?"

"I'm not a _child_ ," protested Sheppard, looking wounded. "I'm sixteen. That's legal age now, isn't it? Or almost, anyway." He made a lewd gesture at Rodney. "You want to have sex with me?"

"I do _not_!" snapped Rodney, horrified. "I'm not a _pedophile_!"

"Oh, come on," Sheppard objected. "It'd be great. I'm attractive, you're attractive- true, I'm more attractive than you are-"

"We are so not having this conversation," Rodney announced, and went back to his work, attempting to tune Sheppard out with all his might.

Sheppard let out an offended little huff of air, and flounced out the door.

~~~

"So," said Sheppard at dinner that night. "Are there any hot Athosian teenagers on your planet, Teyla? Because McKay won't have sex with me, and if he won't, I don't think anyone else will, either."

Rodney bit into his roll a bit harder than was strictly necessary. Ronon smirked at him, and Teyla eyed him warily. Lorne and Zelenka, eating with them tonight, shared shocked, amused looks.

"Seriously," Sheppard pressed, apparently oblivious to the consternation he was causing. "Are there? Because apparently my current girlfriend is now, like, forty, and lives on another planet. In another _galaxy_ , for Christ's sake. And hey- if there aren't any girls, are there any pretty guys?"

"There are...many attractive Athosian youths," said Teyla cautiously. "I doubt, however, that any of them would be interested in you."

"Oh, ouch, that's rough," Sheppard said, and plastered a mock-hurt expression on his face.

Teyla hurried to correct her statement. "I did not mean to offend you by that, John. I merely meant that since you will be returning to your proper age and status eventually, there is no point in getting involved with anyone you might have cause to later regret."

"Especially," Lorne added, and his face twitched a bit at saying this: "Since once you return to your normal age, you're- ah- not going to want to have been involved with someone decades younger than you. And also, you're not allowed to be interested in men. Comes with the job description. Sir."

"Don't call me sir, it's weird," Sheppard told him, and sighed. "Yes, I suppose you're right. About the age thing and the gay thing. Too bad. Guess I won't be able to convince McKay to fuck me now, huh?" He reached for another piece of bread, smirking at the slightly horrified looks being traded around the table.

Rodney imagined stabbing Sheppard with his spork, and decided that rubbing this conversation in Sheppard's face when he returned to normal would be revenge enough.

~~~

Sheppard invaded his privacy a few days later by bursting unannounced into his private quarters.

"Hey!" yelped Rodney, scrambling to conceal the fact that he was reading a medical journal and not wearing pants.

"Radek just kicked my ass at chess," said Sheppard immediately. "I heard somewhere that I used to play with you a lot. And beat you. Wanna play?" He waggled his eyebrows in a way that was clearly meant to be sexy and was also failing miserably.

Rodney scowled at him, surreptitiously shoving the journal under the covers, and feeling around for his pants. "Have you ever heard of knocking?"

"Have you ever heard of sliding doors that open before you get close enough to knock on them?" Sheppard inquired, then looked slightly sheepish. "That is, if you've unlocked them with your mind first. You know, theoretically. Hypothetically."

"You skinny little bastard," Rodney told him. "Also, you have the chess set."

"Okay, then," Sheppard said, and rolled his eyes. "Come on, let's go."

"I do not wish to play chess with you," Rodney said, slowly and carefully and clearly. "I am _busy_."

"Doing what- reading the British Medical Journal?" asked Sheppard dubiously. Rodney flushed- he would never live it down with Carson if word of that got around. But hey- one needed to know the symptoms of any unfortunate plagues one might catch on dangerous planets.

"No," he lied in response to Sheppard's question, and failed to find his pants.

"Uh huh," said Sheppard skeptically, and raised an eyebrow.

"I don't want to play chess with you," Rodney snapped at him, red-faced. "I am- doing things."

"Come _on_ ," Sheppard all but whined, dancing from foot to foot with teenaged impatience. "I'm _bored_."

"I can tell," said Rodney sarcastically. "Did you hear me say no?"

Sheppard wandered further into his room, and flopped down on a chair. "I'll do anything," he said persuasively. " _Anything_ , do you hear me? Just relieve my boredom, oh king of rude statements and woeful boredom!"

"Insulting me isn't going to help, you know," Rodney told him, and sighed. "Fine. Go away. I'll meet you in a couple of minutes, okay?"

"Yes, sure, fine, great!" Sheppard said happily, and sprung youthfully to his feet.

He strode a few steps towards the door, then turned and tossed something at Rodney, who caught it.

"Nice boxers," Sheppard said, smirking, and went out the door, leaving Rodney to realize that Sheppard had found his pants.

"Brat," he muttered, and sighed.

~~~

"Hey," said Sheppard at lunch one day. "I know how to fix me."

Rodney turned to stare at him. "How? You know nothing about Ancient technology."

"I don't need to," Sheppard said cheerfully. "C'mon, think, McKay! What's the one thing you know of that ages people, really fast?"

Rodney frowned at him, not getting it. Teyla shared his bemused look and shook her head silently at him.

Ronon, however, got it immediately. "Wraith," he said, and Rodney let out a horrified yelp.

"You cannot be serious," said Teyla slowly, eyes wide.

"It'd be painful, yeah," said Sheppard. "But hey- it would work!"

"We are _not_ feeding you to a Wraith," Rodney snapped at him, feeling queasy at the thought.

"Awww, McKay, I didn't know you cared," Sheppard drawled, and twirled his spork around his fingers.

Rodney scowled, ignoring an uncomfortable prickling in the region of his heart. "It would be stupid. We'd have no way of forcing the Wraith to stop and start when we'd want it to, short of shooting it and that might have bad effects on you. And capturing a Wraith to do that would be a waste of resources. Furthermore, it wouldn't restore your older identity and personality, it would just make you old and dying!"

Sheppard rolled his eyes. "Jesus, it was just an _idea_ , McKay!"

"A bad one," said Ronon, and Rodney nodded his head vigorously in agreement, not wanting to think of Sheppard being _fed on_ by a _Wraith._

"Whatever," said Sheppard, apparently not too attached to the idea of re-aging-by-Wraith. "Teyla, can I have your sausage?"

~~~

When Zelenka found the answer to the problem of how to re-age Sheppard ( _without_ Wraith involvement), Rodney was happy enough about it that he wasn't even bothered that it was Zelenka and not him who had found the answer. (Mostly not bothered, anyway.)

Elizabeth scheduled Zelenka to go along with their team back to the alien ruin which had de-aged Sheppard in the first place the next morning. Rodney twitched at the delay, and tried not to think about the fact that he was actually going to miss Sheppard the Annoying Teenager of Doom.

Sheppard came into his room that night, looking unexpectedly nervous.

"What's up? What is it?" demanded Rodney groggily. He closed his laptop screen- his equations could wait and he'd been dozing on and off anyway.

"I um," said Sheppard intelligently. "I'm not sure I want to turn back. I mean, I get to live longer like this, don't I? Who wouldn't want three extra decades of life?"

"Way to get second thoughts this late in the game," Rodney muttered, and sighed. "You don't have to turn back, you know. Of course, since a random teenager is a security risk and unnecessary personnel, even _with_ your gene, you'd probably be shipped back off to Earth and be forced to go to high school again. Or college, or whatever."

"That would suck," murmured Sheppard. He came forward and sat down next to Rodney on the bed- tucking his legs up, wrapping his arms around them and leaning his chin on his knees. "I like this place."

"Yeah," said Rodney softly, and resisted the urge to smooth his fingers through Sheppard's still-unruly hair. "I like it, too."

Sheppard considered this for a moment. "Was I- I mean, when I was an adult- people liked me, right?"

"Yeah, of course," said Rodney, surprised, and added: "You got laid a lot, too."

"Did I?" murmured Sheppard softly. "I can't imagine I would _want_ to. You know. Get laid."

Rodney blinked at him, shocked, and said: "Are you kidding me? Who wouldn't want to get laid? And your filthy teenage mind has been focused on sex this entire time- I haven't forgotten you _hitting_ on me," he added, aggrieved.

Sheppard made an indistinct noise, and looked briefly hesitant before turning sideways and pressing his lips to Rodney's.

It was a surprisingly good kiss- Sheppard tasted warm and sunny and wonderful to Rodney's mouth- before he remembered that Sheppard was (by military requirement) straight, and also: a teenager. He gently shoved Sheppard away, and saw his face crumple slightly with hurt.

"See," said Rodney, and tried not to be offensive and awkward and horrible. "See- there's this age difference, between us-"

"Not _really,_ " Sheppard protested. "I'm actually really forty, see-"

"Not right now, you're not," Rodney told him sharply, and then tried to soften his words. "Look- I'm not, we're not- you won't want this in the morning, when you're old enough again."

Sheppard jutted his chin out defiantly. "How do you know? I don't think you even knew I was gay before I de-aged. I don't even know if I knew that you don't know that _you're_ gay."

Rodney took several moments to decipher this, then scowled at him. "I'm _not_ gay. And we're not talking about this, okay? You're going to regret it, if you even remember it, and I'm not a pedophile."

Sheppard clutched at his arm, pleadingly. "I'll change back, then, okay? And you have to promise me something, if I do. You have to promise to kiss me. Or let me kiss you. At least once."

"Sheppard-" said Rodney wearily.

" _Please_ ," said Sheppard, a bit desperately. "C'mon, McKay- promise me."

"All right, fine," Rodney snapped. "Fine! I promise. But only if you want to, afterwards."

Sheppard gazed intently at him for another long moment, as if making sure Rodney was serious about this.

"Okay," he said eventually. "I'll just- see you in the morning, okay?"

Rodney nodded, and watched him leave, not at all sure how he felt.

~~~

The re-aging trip was a complete success. Mini!Sheppard became Normal!Sheppard, although Ronon had to sling him over his shoulder and haul him back to Atlantis like that because the process rendered him unconscious.

Rodney refused to wait in the infirmary for Sheppard to wake up like he usually did. They didn't know if he would remember anything from his side trip into his lost youth, and if he did, Rodney did not want to have That Conversation about The Promised Kiss any time soon. Or any time at all, actually.

It didn't help that however (disturbingly) attractive Sheppard had been as a teenager, he was several times more so as an adult. Plus, Rodney didn't feel awkward about said attractiveness now that they were the same age.

Sheppard was doomed to wake up eventually, however, and almost as soon as he did, he went and found Rodney and dragged him out of his lab and into a nearby secluded closet-room-thing.

"Hi, nice to see you too," Rodney said sarcastically, and rubbed his arm pointedly where Sheppard had grabbed it. "You remember anything about your second childhood?"

Sheppard smirked at him- something his teenage self had done, too- and leaned back against the wall. "I remember everything, actually," he said, deceptively casual.

Rodney felt a squirm of discomfort in his stomach. "Oh?" he said, going for the same tone of deceptive casualness, and failing squeakingly.

"Yeah," said Sheppard, still watching him with an intent self-control his teenage self certainly hadn't possessed. "Thanks for not feeding me to a Wraith. I was kind of an idiot as a teenager."

"Whatever, think nothing of it," said Rodney hastily, waving a hand in dismissal. He added, feeling slightly betrayed: "Also, why didn't you tell me you'd gone to MIT? At age _sixteen_?"

"I was seventeen a month after I got there," said Sheppard mildly. "Also, I dropped out halfway through my sophomore year and joined the Air Force instead. I didn't think my year and a half of college was all that important."

"Yes, well," Rodney muttered. "I suppose you _did_ tell me that you could've been Mensa. And you had a _ponytail_!" he added, pointing a finger at Sheppard, who rolled his eyes.

"Yes, because my teenaged hairstyle of choice is incredibly relevant to my adult life. Chill out, McKay."

Rodney scowled at him, and crossed his arms. "Yes, well-" he began, and failed to think of an appropriate insult. It was hard to think properly, with Sheppard just leaning there and _looking_ at him like that.

Apparently, though, Sheppard had had enough of looking, and decided to act. He crossed the closet-room-thing in three quick steps and pressed his mouth to Rodney's. Rodney tipped his head back, and let Sheppard press him against the wall. He fisted his fingers in Sheppard's shirt, and kissed him back. Sheppard sucked hungrily at Rodney's bottom lip for a moment, before drawing away. Rodney slumped back against the wall, breathless.

"So, McKay," Sheppard drawled, looking smug. "Tell me you're not gay again?"

"You idiot," said Rodney. "I'm bisexual," and kissed him again.


End file.
